SDK Toolset (FSX)
From FSDeveloper Wiki
The components of each SDK, with links to the documentation describing how to use it.
The SDK is actually a collection of task-oriented SDKs.
There is no single tool that you run,
rather it's collection of tools, each of which perform seperate tasks.
The majority of tools are stand-alone, and launched outside of the sim.
You should use the appropriate SDK version to match your version of FS.
The only SDK tools available in-game, are the Object placement tool, 3 traffic tools, and the effects tool.
All other tools are run/started from outside the sim GUI.
SDK documentation, and access links to some tools, are available from -
RTM, SP1, & SP1a documentation is supplied in html format, with each folder containing the relevant html file(s).
SP2 documentation is supplied in chm format, as a single compiled html file, fsxsdk.chm.
You can search within open pages,
 Core Utilities Kit
 Environment Kit
 Mission Creation Kit
 SimObject Creation Kit
 Acceleration Expansion Pack SDK